package com.dc.base.util;

import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;

public class AESUtil {
	
	private static byte[] keyValue = new byte[] {       //用户密钥  
        22,25,-35,-45,25,98,-55,-45,10,35,-45,25,  
        26,-95,25,-65,-78,-99,85,45,-62,10,-0,11,  
        -35,48,-98,65,-32,14,-78,25,36,-56,-45,-45,  
        12,15,-35,-75,15,-14,62,-25,33,-45,55,68,-88  
    };  
    private static byte[] iv = new byte[] {             //算法参数  
        -12,35,-25,65,45,-87,95,-22,-15,45,55,-66,32,5-4,84,55  
    };  
    private static SecretKey key;                       //加密密钥  
    private static AlgorithmParameterSpec paramSpec;    //算法参数  
    private static Cipher ecipher;                      //加密算法  
      
    static{       
        KeyGenerator kgen;  
        try {  
            //为指定算法生成一个密钥生成器对象。  
            kgen = KeyGenerator.getInstance("AES");  
            //使用用户提供的随机源初始化此密钥生成器，使其具有确定的密钥长度。  
            kgen.init(128, new SecureRandom(keyValue));  
            //使用KeyGenerator生成（对称）密钥。  
            key = kgen.generateKey();  
            //使用iv中的字节作为IV来构造一个 算法参数。  
            paramSpec = new IvParameterSpec(iv);  
            //生成一个实现指定转换的 Cipher 对象  
            ecipher = Cipher.getInstance("AES/CBC/PKCS5Padding");         
        } catch (NoSuchAlgorithmException e) {  
            e.printStackTrace();  
        } catch (NoSuchPaddingException e) {  
            e.printStackTrace();  
        }  
    }  
  
    /** 
     * 加密，使用指定数据源生成密钥，使用用户数据作为算法参数进行AES加密 
     * @param msg 加密的数据 
     * @return 
     */  
    public static String encrypt(String msg) {  
        String str = "";  
        try {             
            //用密钥和一组算法参数初始化此 cipher  
            ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);  
            //加密并转换成16进制字符串  
            str = asHex(ecipher.doFinal(msg.getBytes()));  
        } catch (BadPaddingException e) {  
            e.printStackTrace();  
        } catch (InvalidKeyException e) {  
            e.printStackTrace();  
        } catch (InvalidAlgorithmParameterException e) {  
            e.printStackTrace();  
        } catch (IllegalBlockSizeException e) {  
            e.printStackTrace();  
        }  
        return str;  
    }  
      
    /** 
     * 解密，对生成的16进制的字符串进行解密 
     * @param value 解密的数据 
     * @return 
     */  
    public static String decrypt(String value) {  
        try {  
            ecipher.init(Cipher.DECRYPT_MODE, key, paramSpec);  
            return new String(ecipher.doFinal(asBin(value)));  
        } catch (BadPaddingException e) {  
            e.printStackTrace();  
        } catch (InvalidKeyException e) {  
            e.printStackTrace();  
        } catch (InvalidAlgorithmParameterException e) {  
            e.printStackTrace();  
        } catch (IllegalBlockSizeException e) {  
            e.printStackTrace();  
        }  
        return "";  
    }  
  
    /** 
     * 将字节数组转换成16进制字符串 
     * @param buf 
     * @return 
     */  
    private static String asHex(byte buf[]) {  
        StringBuffer strbuf = new StringBuffer(buf.length * 2);  
        int i;  
        for (i = 0; i < buf.length; i++) {  
            if (((int) buf[i] & 0xff) < 0x10)//小于十前面补零  
                strbuf.append("0");  
            strbuf.append(Long.toString((int) buf[i] & 0xff, 16));  
        }  
        return strbuf.toString();  
    }  
  
    /** 
     * 将16进制字符串转换成字节数组 
     * @param src 
     * @return 
     */  
    private static byte[] asBin(String src) {  
        if (src.length() < 1)  
            return null;  
        byte[] encrypted = new byte[src.length() / 2];  
        for (int i = 0; i < src.length() / 2; i++) {  
            int high = Integer.parseInt(src.substring(i * 2, i * 2 + 1), 16);//取高位字节  
            int low = Integer.parseInt(src.substring(i * 2 + 1, i * 2 + 2), 16);//取低位字节  
            encrypted[i] = (byte) (high * 16 + low);  
        }  
        return encrypted;  
    }  

    public static void main(String[] args){
    	String a = "111111";
    	System.out.println(encrypt(a));
    	
    }
}
